Changeset 1272 in webkit for trunk/JavaScriptCore/kjs/ustring.h

Timestamp:

Jun 4, 2002, 3:33:26 PM (23 years ago)

Author:

darin

Message:

Improve the speed of the JavaScript string append operation by growing
the capacity so we don't need to reallocate the string every time.

Also fix script execution so it doesn't use recursion to advance from
one statement to the next, using iteration instead.

• Makefile.am: Stop using BUILT_SOURCES to build JavaScriptCore-stamp, because this causes the Project Builder project to build *before* the subdir. Intead, use an all-am rule in a way more similar to all our other directories.

• kjs/grammar.y: Link the SourceElementsNode in the opposite direction, so we can walk the list and execute each element instead of using recursion to reverse the list.
• kjs/grammar.cpp: Check in new generated file.

• kjs/nodes.cpp: (SourceElementsNode::execute): (SourceElementsNode::processFuncDecl): (SourceElementsNode::processVarDecls): Use loops instead of recursion.

• kjs/ustring.h: Don't initialize all UChar objects to 0. This was wasting a *huge* amount of time.
• kjs/ustring.cpp: (UString::Rep::create): Add a "capacity" along with the length. (UString::append): Include 50% extra capacity when appending. (UString::operator=): Reuse the buffer if possible rather than always creating a new one.

File:

• trunk/JavaScriptCore/kjs/ustring.h (modified) (5 diffs)

trunk/JavaScriptCore/kjs/ustring.h

@@ -57 +57 @@
    */
   struct UChar {
-    /**
-     * Construct a character with value 0.
-     */
+#ifdef APPLE_CHANGES
+    /**
+     * Construct a character with uninitialized value.    
+     */
+#else
+    /**
+     * Construct a character with value 0.    
+     */
+#endif
     UChar();
     /**
@@ -108 +114 @@
   };
 
+#ifdef APPLE_CHANGES
   inline UChar::UChar() : uc(0) { }
+#else
+  inline UChar::UChar() { }
+#endif
   inline UChar::UChar(unsigned char h , unsigned char l) : uc(h << 8 | l) { }
   inline UChar::UChar(unsigned short u) : uc(u) { }
@@ -210 +220 @@
       UChar *dat;
       int len;
+#ifdef APPLE_CHANGES
+      int capacity;
+#endif
       int rc;
       static Rep null;
@@ -232 +245 @@
      */
     UString(const UChar *c, int length);
+#ifdef APPLE_CHANGES
+    /**
+     * If copy is false the string data will be adopted.
+     * That means that the data will NOT be copied and the pointer will
+     * be deleted when the UString object is modified or destroyed.
+     * Behaviour defaults to a deep copy if copy is true.
+     */
+#else
     /**
      * If copy is false a shallow copy of the string will be created. That
@@ -238 +259 @@
      * Behaviour defaults to a deep copy if copy is true.
      */
+#endif
     UString(UChar *c, int length, bool copy);
     /**